SELECT pg_get_functiondef(p.oid), p.prosrc
FROM pg_proc p
WHERE proname='gen_ersave'

select * from  pg_proc WHERE proname='gen_ersave'

select * from  pg_proc WHERE proname='gen_ersave'

test=# \x
Expanded display is on.
test=# select * from pg_proc where proname='pgcompact_clean_pages_57793';
-[ RECORD 1 ]---+--------------------------------------------------------------------------------
proname         | pgcompact_clean_pages_57793
pronamespace    | 2200
proowner        | 10
prolang         | 12727
procost         | 100
prorows         | 0
provariadic     | 0
protransform    | -
proisagg        | f
proiswindow     | f
prosecdef       | f
proleakproof    | f
proisstrict     | f
proretset       | f
provolatile     | v
pronargs        | 5
pronargdefaults | 0
prorettype      | 23
proargtypes     | 25 25 23 23 23
proallargtypes  |
proargmodes     |
proargnames     | {i_table_ident,i_column_ident,i_to_page,i_page_offset,i_max_tupples_per_page}
proargdefaults  |
prosrc          |
                | DECLARE
                |     _from_page integer := i_to_page - i_page_offset + 1;
                |     _min_ctid tid;
                |     _max_ctid tid;
                |     _ctid_list tid[];
                |     _next_ctid_list tid[];
                |     _ctid tid;
                |     _loop integer;
                |     _result_page integer;
                |     _update_query text :=
                |         'UPDATE ONLY ' || i_table_ident ||
                |         ' SET ' || i_column_ident || ' = ' || i_column_ident ||
                |         ' WHERE ctid = ANY($1) RETURNING ctid';
                | BEGIN
                |     -- Check page argument values
                |     IF NOT (
                |         i_page_offset IS NOT NULL AND i_page_offset >= 1 AND
                |         i_to_page IS NOT NULL AND i_to_page >= 1 AND
                |         i_to_page >= i_page_offset)
                |     THEN
                |         RAISE EXCEPTION 'Wrong page arguments specified.';
                |     END IF;
                |
                |     -- Check that session_replication_role is set to replica to
                |     -- prevent triggers firing
                |     IF NOT (
                |         SELECT setting = 'replica'
                |         FROM pg_catalog.pg_settings
                |         WHERE name = 'session_replication_role')
                |     THEN
                |         RAISE EXCEPTION 'The session_replication_role must be set to replica.';
                |     END IF;
                |
                |     -- Define minimal and maximal ctid values of the range
                |     _min_ctid := (_from_page, 1)::text::tid;
                |     _max_ctid := (i_to_page, i_max_tupples_per_page)::text::tid;
                |
                |     -- Build a list of possible ctid values of the range
                |     SELECT array_agg((pi, ti)::text::tid)
                |     INTO _ctid_list
                |     FROM generate_series(_from_page, i_to_page) AS pi
                |     CROSS JOIN generate_series(1, i_max_tupples_per_page) AS ti;
                |
                |     <<_outer_loop>>
                |     FOR _loop IN 1..i_max_tupples_per_page LOOP
                |         _next_ctid_list := array[]::tid[];
                |
                |         -- Update all the tuples in the range
                |         FOR _ctid IN EXECUTE _update_query USING _ctid_list
                |         LOOP
                |             IF _ctid > _max_ctid THEN
                |                 _result_page := -1;
                |                 EXIT _outer_loop;
                |             ELSIF _ctid >= _min_ctid THEN
                |                 -- The tuple is still in the range, more updates are needed
                |                 _next_ctid_list := _next_ctid_list || _ctid;
                |             END IF;
                |         END LOOP;
                |
                |         _ctid_list := _next_ctid_list;
                |
                |         -- Finish processing if there are no tupples in the range left
                |         IF coalesce(array_length(_ctid_list, 1), 0) = 0 THEN
                |             _result_page := _from_page - 1;
                |             EXIT _outer_loop;
                |         END IF;
                |     END LOOP;
                |
                |     -- No result
                |     IF _loop = i_max_tupples_per_page AND _result_page IS NULL THEN
                |         RAISE EXCEPTION
                |             'Maximal loops count has been reached with no result.';
                |     END IF;
                |
                |     RETURN _result_page;
                | END
probin          |
proconfig       |
proacl          |